UNISONIC TECHNOLOGIES CO., LTD ELECTRONIC TONE RINGER WITH BUILT-IN BRIDGE DESCRIPTION The UTC LS1240A is monolithic integrated circuits and designed to be as a telephone ringer. It can drive a piezo-ceramic converter(buzzer) directly. The output current capacity of UTC LS1240A is higher than standard ringer. For driving a dynamic loudspeaker, UTC LS1240A needs only a decoupling capacitor to replace the usual transformer in use. FEATURES * Low current consumption. * Integrated rectifier bridge with zener diodes to overvoltage Protection. * Minimum external circuitry. * Both frequencies of tone and switching are adjustable by external components. * Integrated voltage and current hysteresis. ORDERING INFORMATION Ordering Number Lead Free Halogen Free Package Packing LS1240AL-D08-T LS1240AG-D08-T DIP-8 Tube LS1240AL-S08-R LS1240AG-S08-R SOP-8 Tape Reel LS1240AL-S08-T LS1240AG-S08-T SOP-8 Tube 1 of 5 Copyright 2012 Unisonic Technologies Co., Ltd
PIN CONFIGURATION 1 8 GND 2 UTC LS1240A Cr CSW 3 6 NULL Ra 4 5 OUT PIN DESCRIPTION PIN PIN NAME DESCRIPTION 1 Connecting pin to B-wire 2 GND Ground 3 Csw Sweep rate control capacitor 4 Ra Output frequency control resistor 5 OUT Buzzer 6 NULL Not connected Cr Rectifier capacitor 8 Connecting pin to A-wire UNISONIC TECHNOLOGIES CO., LTD 2 of 5
BLOCK DIAGRAM TELEPHONE 1 IN BRIDGE IN 8 TELEPHONE GND 2 CAPACITOR SWEEP RATE CONTROL CAPACITOR 3 SWITCHING FREQUENCY GENERATOR THRESHOLD CIRCUIT WITH HYSTERESIS 6 N.C. OUTPUT FREQYENCY CONTROL RESISTOR 4 NONE FREQUENCY GENERATOR OUTPUT STAGE 5 BUZZER TEST CIRCUIT 1 F 2.2k 8 5 VAB UTC LS1240A RL Vout 10 F 1 2 3 4 C1 100nF R1 14k R1= 2200 f1(hz) *(1-0.04 In f1 1943 ) f2=0.25f1 fsweep = 50 C1(nF) UNISONIC TECHNOLOGIES CO., LTD 3 of 5
ABSOLUTE MAXIUM RATINGS PARAMETER SYMBOL RATINGS UNIT Calling Voltage (f=50hz) Continuous V ABθ 120 V RMS Calling Voltage (f=50hz) (5s ON/10s OFF) V AB 200 V RMS Supply Current I DC 30 ma Operating Temperature T OPR -40 ~ +0 C Storage Temperature T STG -65 ~ +150 C Note Absolute maximum ratings are those values beyond which the device could be permanently damaged. Absolute maximum ratings are stress ratings only and functional device operation is not implied. THERMAL DATA PARAMETER SYMBOL RATINGS UNIT SOP-8 150 Junction to Ambient θ JA /W DIP-8 100 ELECTRICAL CHARACTERISTICS (T A = 25, unless otherwise specified) PARAMETER SYMBOL TEST CONDITIONS MIN TYP MAX UNIT Supply Voltage V S 26 V Current Consumption without load I B V S =9.3 to 25V 1.5 1.8 ma Activation Voltage V ON 12 13.5 V Sustaining Voltage V OFF.8 9.3 V Differential Resistance in OFF Condition R D 6.4 kω Output Voltage Swing V OUT V S -5 V Short Circuit Current I OUT V S =20V, R L =250Ω 0 ma AC OPERATION Output Frequencies (Vs=26V,R1=14kΩ) f OUT1 V 3 =0V 1.55 2.53 f OUT2 V 3 =6V 1.08 1.9 khz Fout1/Fout2 1.33 1.43 Programming Resistor Range 8 56 kω Sweep Frequency C1=100nF,R1=14kΩ 5.25.5 9.5 Hz UNISONIC TECHNOLOGIES CO., LTD 4 of 5
TYPICAL APPLICATION CIRCUIT No current limitation is provided on the output stage of UTC LS1240A, so a minimum load DC of 50 ohms is advised. The two tone frequencies generated are switched by an internal oscillator in a fast sequence and made audible across an output amplifier in the loudspeaker, both tone frequencies and the switching frequency can be externally adjusted. The signal and the circuit is designed so that noise on the line or variations of the ringing signal cannot affect correct operation of the device. UTC assumes no responsibility for equipment failures that result from using products at values that exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or other parameters) listed in products specifications of any and all UTC products described or contained herein. UTC products are not designed for use in life support appliances, devices or systems where malfunction of these products can be reasonably expected to result in personal injury. Reproduction in whole or in part is prohibited without the prior written consent of the copyright owner. The information presented in this document does not form part of any quotation or contract, is believed to be accurate and reliable and may be changed without notice. UNISONIC TECHNOLOGIES CO., LTD 5 of 5